[PortsJ] Some error handling and improved number parsing

Author: codeZeilen

ports-j/jscheme/src/main/java/Closure.java

@@ -1,4 +1,3 @@
-package java;
 
 /**
  * A closure is a user-defined procedure.  It is "closed" over the

ports-j/jscheme/src/main/java/Continuation.java

@@ -1,4 +1,3 @@
-package java;
 
 /**
  * @author Peter Norvig, peter@norvig.com http://www.norvig.com

ports-j/jscheme/src/main/java/Environment.java

@@ -1,4 +1,3 @@
-package java;
 
 /**
  * Environments allow you to look up the value of a variable, given
@@ -59,6 +58,9 @@ public Object lookup(String symbol) {
      * Add a new variable,value pair to this environment.
      */
     public Object define(Object var, Object val) {
+        if(!(var instanceof String)) {
+            error("Can only define symbols, got" + var + "instead.");
+        }
         vars = cons(var, vars);
         vals = cons(val, vals);
         if (val instanceof Procedure && ((Procedure) val).name.equals("anonymous procedure"))

ports-j/jscheme/src/main/java/InputPort.java

@@ -1,11 +1,11 @@
-package java;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.Reader;
 
 import java.math.BigInteger;
+import java.math.BigDecimal;
 
 /**
  * InputPort is to Scheme as InputStream is to Java.
@@ -264,16 +264,18 @@ Object nextToken() throws IOException {
                 // Try potential numbers, but catch any format errors.
                 if (c == '.' || c == '+' || c == '-' || (c >= '0' && c <= '9')) {
                     String numString = buff.toString();
-                    if(numString.contains(".") && numString.length() > 1) {
+                    if((numString.contains(".") || numString.contains("e-")) && numString.length() > 1) {
                         // We need to manually check, as 2.0 might end up as 2 otherwise
                         try {
-                            return Double.valueOf(numString);
+                            // We use the detour through BigDecimal to get e notation parsing
+                            return new BigDecimal(numString).doubleValue();
                         } catch (NumberFormatException e2) {
                             ;
                         };
                     } else {
                         try {
-                            return new BigInteger(numString);
+                            // We use the detour through BigDecimal to get e notation parsing
+                            return new BigInteger(new BigDecimal(numString).toPlainString());
                         } catch (NumberFormatException e1) {
                             ;
                         }

ports-j/jscheme/src/main/java/JavaMethod.java

@@ -1,4 +1,3 @@
-package java;
 
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;

ports-j/jscheme/src/main/java/Macro.java

@@ -1,4 +1,3 @@
-package java;
 
 /**
  * @author Peter Norvig, peter@norvig.com http://www.norvig.com

ports-j/jscheme/src/main/java/Pair.java

@@ -1,4 +1,3 @@
-package java;
 
 /**
  * A Pair has two fields, first and rest (or car and cdr).

ports-j/jscheme/src/main/java/Primitive.java

@@ -1,4 +1,3 @@
-package java;
 
 import java.io.*;
 import java.lang.reflect.InvocationTargetException;

ports-j/jscheme/src/main/java/Procedure.java

@@ -1,4 +1,3 @@
-package java;
 
 /**
  * @author Peter Norvig, peter@norvig.com http://www.norvig.com

ports-j/jscheme/src/main/java/Scheme.java

@@ -1,4 +1,3 @@
-package java;
 
 import java.io.FileInputStream;
 import java.io.IOException;
@@ -57,6 +56,7 @@ public void readEvalWriteLoop() {
                 output.print("> ");
                 output.flush();
                 if (input.isEOF(x = input.read())) return;
+                x = expand(x);
                 write(eval(x), output, true);
                 output.println();
                 output.flush();
@@ -85,6 +85,7 @@ public Object load(InputPort in) {
         Object x = null;
         for (; ; ) {
             if (in.isEOF(x = in.read())) return TRUE;
+            x = expand(x);
             eval(x);
         }
     }
@@ -106,7 +107,10 @@ public Object eval(Object x, Environment env) {
             } else {
                 Object fn = first(x);
                 Object args = rest(x);
-                if (fn == "quote") {             // QUOTE
+                if (fn == "quote") { // QUOTE
+                    if(rest(args) != null) {
+                        error("Quote only accepts one argument got " + args);
+                    }
                     return first(args);
                 } else if (fn == "begin") {      // BEGIN
                     for (; rest(args) != null; args = rest(args)) {
@@ -121,6 +125,9 @@ public Object eval(Object x, Environment env) {
                 } else if (fn == "set!") {       // SET!
                     return env.set(first(args), eval(second(args), env));
                 } else if (fn == "if") {         // IF
+                    if(length(args) > 3) {
+                        error("if accepts only three arguments at most got " + args);
+                    }
                     x = (truth(eval(first(args), env))) ? second(args) : third(args);
                 } else if (fn == "cond") {       // COND
                     x = reduceCond(args, env);
@@ -155,7 +162,7 @@ public Object eval(Object x) {
      * Eval a String
      */
     public Object eval(String str) {
-        return eval((new InputPort(new StringReader(str))).read());
+        return eval(expand((new InputPort(new StringReader(str))).read()));
     }
 
     /**
@@ -191,6 +198,11 @@ else if (second(clause) == "=>")
         }
     }
 
+
+    private Object expand(Object x) {
+        return x;
+    }
+
 }